Andrew Gallatin writes: > > Peter Memishian writes: > > > > > If you receive a packet addressed to MAC address "B" in promisc mode > > > on an interface using MAC address "A", with IP listening, will there > > > be a copy? > > > > > > I assumed there would be, but I don't understand the code well enough > > > to know for sure. My concern was that if there is a copy, it seems > > > pointless, since the mis-addressed packet should not make it to IP. > > > > AFAIK IP will get a copy in that case (assuming the packet is IPv4 or > > IPv6). But how common is such a situation in modern switched networks? > > Probably fairly unusual, to be sure. But I think there are switches > which can be configured to shunt a copy of all traffic to a designated > port.
I'd expect behavior like that to cause some really undesirable effects. If the system is configured as a router, you'll get spurious redirects or even duplicated packets flowing through your network as a result. It might even be considered a security or "privacy" problem in some contexts. If there's any decent way to make sure that "not addressed for self" packets aren't inadvertently sent up the unicast non-promiscuous streams (such as the ones IP is using), we should probably do that. Only a promiscuous stream should get those. -- James Carlson, Solaris Networking <[EMAIL PROTECTED]> Sun Microsystems / 35 Network Drive 71.232W Vox +1 781 442 2084 MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677 _______________________________________________ networking-discuss mailing list [email protected]
